The present invention relates to the treatment of pregnant women and more particularly to a mattress device for treating a pregnant woman lying in the ventral position.
In the past, there have been proposed mattresses having a cavity located in the central portion and adapted to accommodate the enlarged abdomen of an expectant mother sleeping or resting in a face-down position. In U.S. Pat. No. 3,378,862 issued on Apr. 23, 1968 to J. P. Skinner, there is disclosed a foam rubber mattress having a cavity shaped to accommodate the expanded abdomen of a woman in full term pregnancy, with a stretchable panel covering the top of the cavity so as to support the expanded abdomen. The panel thereby is designed to serve as a continuing support for the expanded abdomen during the progressive stages of pregnancy since it provides a resistance or tension on the abdominal wall. In U.S. Pat. No. 3,118,152 issued on Jan. 21, 1964 to R. B. Talley, Jr., there is disclosed a maternity mattress pad made up of sections around a central opening. Also, in U.S. Pat. No. 3,287,747 issued on Nov. 29, 1966 to Ellsworth, there is disclosed a maternity mattress abdominal cushion having an elliptical shape in plan contour.
Generally, the known attempts to place pregnant women in the ventral or prone position were intended primarily for comfort reasons and to satisfy the habit of those patients that sleep on their stomachs. The prior art mattress devices have cavities or depressions for accommodating the pregnant uterus, but only in a minimal degree or in no manner do such mattresses relieve the pressure caused by the pregnant uterus or by the abdominal wall on the abdominal aorta. Such mattresses or cushions generally produce a pressure on the abdominal wall through the bottom or sides of the cavity walls or the cushion.
Conventional mattresses are designed with substantially equal distribution of spring or padding support throughout the mattress. For the pregnant woman sleeping or resting in the prone position the expanded abdomen, in addition to its enlarged size, presents a concentration of body weight in one area of the mattress. Therefore, it is also desirable to provide a mattress for the pregnant woman which not only supports the pregnant woman lying in the prone or ventral position with her abdominal wall floating freely, but also adequately supports the entire body especially in the heavier region around the midsection. By supporting the patient in the ventral position with the abdominal wall floating freely, the uterus will be pressing on the abdominal wall rather than on the abdominal aorta. This eliminates possible consequences of pressure on the abdominal aorta, namely, the interference with the blood supply to the lower half of the body including the pregnant uterus, leading to serious complications such as fetal distress and toxemia.
Also, vacuum devices have been employed for treating pregnant women, such as the rigid cylindrical drum fitted around the midsection with a sack and extension enclosing the legs and feet, as disclosed in U.S. Pat. No. 3,642,006 issued on Feb. 15, 1972 to W. Wobbe. There, the woman stands in the sack and, the partial vacuum causes a strengthening of the blood penetration in the abdominal region. In U.S. Pat. No. 3,062,215 issued on Nov. 6, 1962 to O. S. Heyns, there is disclosed a suction dome applied to the abdomen and a flexible suit receiving suction while the patient is in the dorsal, sitting or standing position, to thereby stimulate labor by distending the abdominal wall outwardly, while the part of the suit around the legs collapses to maintain the legs at substantially atmospheric pressure.
The known vacuum devices are designed primarily for use while the patient is in the dorsal, sitting or standing position. While such devices provide relief to abdominal wall tension, they do not relieve the pressure of the pregnant uterus on the abdominal aorta since the suction pulls on the wall rather than on the uterus. Furthermore, such devices are bulky and cumbersome and therefore can be used for only a few hours without serious discomfort. Also, it is apparent that a patient could not sleep through the night with such equipment.